This gene encodes a member of a family of neuronal cell surface proteins. Members of this family may act as splice site-specific ligands for beta-neurexins and may be involved in the formation and remodeling of central nervous system synapses. Mutations in this gene may be associated with autism and Asperger syndrome. Multiple transcript variants encoding distinct isoforms have been identified for this gene, but their full length sequences have not been determined. [provided by RefSeq].